Robotic Grinding Center for Surface Finishing

De-gating,
de-burring, grinding and polishing – these are the time-intensive
mechanical processing activities that, depending on the batch size,
are increasingly being handled by robots. Increasingly, companies
have turned to these modern robotic grinding centers for greater
efficiency and to provide their customers with high quality services.

“Full
service as a competent specialist for all surfaces” is the slogan
SGA uses to showcase its capabilities and promise its customers a
comprehensive range of services in the fields of barrel finishing,
abrasive blasting, de-gating, grinding, polishing and cleaning of
metallic parts. In addition, SGA supplements its portfolio with
sawing and working on cut parts, as well as material hardening using
abrasive blasting techniques. Mr. Steffen Berner, CEO, and his team
offer customers the entire process chain in industrial surface
finishing. SGA has a rich history of experience. The company was
founded in 1993 and initially began operations with vibratory
finishing and associated waste water technology. With the emergence
of “closed” barrel finishing systems, the business with waste
water technology declined, and the company searched for complementary
new business divisions.

The
company zeroed in on services in the surface finishing sector, namely
in the form of de-burring, grinding and polishing work for all kinds
of parts. The demand for these
services
far exceeded their best expectations, and SGA experienced rapid
growth over the years. Their sustained growth which is reflected by
its modern corporate buildings and a comprehensive machinery and
system park.

SGA
selected SHL as its partner for the implementation of such a flexible
and high-performance de-burring, grinding and polishing system, since
SHL had been building robotic grinding and polishing cells for years.
SHL enjoys the advantage, when compared to so-called robotic system
houses, that it not only integrates robots and creates special
equipment, but it is also able to supply de-burring, grinding and
polishing machines from a single source within its own premises. In
addition, SHL also takes care of the
material flow and material handling peripheral devices, including
service, so that the customer gets a complete, secure and safe system
for handling the process from a one-stop shop resource. Mr. Steffen
Berner and his colleagues first placed an order in 2005 for a SHL
robotic grinding system with one robot. The system primarily
consisted of one 6-axis industrial robot, Kuka KR 30/3, for handling
loads up to 30 kg, two SHL belt conveyor and contact wheel grinding
machines, FKS 250/450 ROB, specially designed for aluminum
processing, and correspondingly certified by TÜV, one scotch
assembly, P550 ROB, clamping devices, tool change set, one pallet and
positioning system, various pallets with fixtures for specific parts,
one dust-protected enclosure, the controller, software and processing
programs for various work-pieces. After a brief period in which SGA
became familiar with the new system, it developed the robotic system
into an “endurance runner”, which is capable of operating in
three shifts for producing highly productive, high-quality and
economically finished customer parts.

It
worked so well that both existing and new customers expressed the
need for additional requirements and demanded higher handling
capacity. As a result, this led to substantial plant and system
expansion in the year 2006 with the addition of another robotic
finishing station. This reaffirmed SHL’s competence for the
engineering, construction and integration of robotic systems. The
modular design permitted the installation of another robotic cell
without having to revamp the entire plant all over again.

Modular
Design

The
modification and expansion program included another 6-axis industrial
robot, Kuka KR 30/3, the extension and adaptation of the pallet
conveyor system, other product-specific grippers, an additional
switching cabinet and mechanical as well as controller-specific
adaptation.

Consequently,
the robotic plant represents the robotic de-burring, grinding and
finishing system today with the two cells for de-burring / grinding
and finishing, whereby both cells can operate jointly or separately
as required. The pallet conveyor system acts as the link, which
allows specifically coded pallets to be linked with specific cells
and operations.

Based
on this design, the robot fetches one part, takes it to the
de-burring and grinding station, and puts it back in its original
location after processing it. Once it has processed all of the parts
in the pallet, it sends the parts on the conveyor to the finishing
cell where the parts undergo the finishing process. Alternatively,
both cells can be fed with different parts, which provides a higher
degree of flexibility in terms of application and utilization. Using
the combination of robot flexibility and the de-burring / grinding
and finishing services, it is possible to work and produce in three
shifts either with a skeleton workforce or with no manpower at all.

With
this in mind, Mr. Steffen Berner said: “We work from 5:00 AM in the
morning to 11:00 PM in the evening under supervision. In the night,
the robotic plant works completely self-sufficiently. Since we have
throughput times of 70 or even 140 seconds per part (in the case of
complex and time-consuming parts), process and operational safety and
security are of great significance. Using the robotic technology, we
are not only highly flexible in terms of universal processing
capability, but we also achieve precise and accurate reproducibility
with respect to quality.When
operating sequentially in both cells one after another for complete
processing, the two robots are synchronized and run synchronously.
This prevents non-productive waiting periods and ensures greater
throughput and efficiency per unit of time. Using the SHL system, we
have been able to enhance our performance tremendously and expand
our customer base remarkably.

The
SHL system is not unlike a universal processing center. We have a
high-performance based system and only need to change the grippers
and fixtures in the pallets and the processing programs of the robots
respectively.”